Typewriter eraser



May 7, 1957 Filed Nov. 19, 1954 E. M. PAREDES 2,791,313

TYPEWRITER ERASER 3 Sheets-Sheet l INVENTOR.

' EENESTQ M47505 P425058,

- y 7, 1957 E. M. PAREDES 2,791,313

TYPEWRITER ERASER I Filed Nov. 19, 1954 3 Sheets-Sheet 2 INVENTOR. EE/VESTO M4 7506 P485556) M y 7, 1957 E. M. PAREDES 2,791,313

' TYPEWRITER ERASER Filed Nov. 19; 1954 a Sheets-Sheet s 4 INVENTOR. EBA/Es T0 M4 7506 P425055;

TYPEWRITER ERASER Ernesto Mateus Paredes, Quito, Ecuador Application November 19, 1954, Serial No. 470,068

3 Claims. (Cl- 197-181) The present invention relates to an electrically driven eraser to be incorporated in a typewriter either as an attachment or as a component part thereof.

The present invention has for its primary object to provide an electrically driven eraser for attachment to a typewriter for erasing letters and words from sheets vof paper carried by the platen of the typewriter.

Another object of the present invention is to provide a reciprocating type of electrically driven eraser, and one which is carried by an arm positioned between the type bars of the typewriter for movement into contact with the paper on the platen of the typewriter in the position where the type bars normally strike the paper on the platen.

A further object of the present invention is to provide an attachment for a typewriter having an arm supporting a reciprocatingly driven eraser in which, when the arm is swung into the platen contacting position, the mechanism for imparting the reciproeatory motion to the eraser is set in motion and such mechanism continues to operate as long as the arm is in its platen contacting position.

A still further object of the present invention s to provide an inexpensively constructed, easily assembled, electrically driven eraser attachment for universal use upon all typewriters.

These and other objects and advantages of the present invention will be fully apparent from the following description when taken in connection with the annexed drawings, in which:

Figure 1 is a side view in elevation of a typewriter showing the present invention installed thereon,

Figure 2 is a partial top plan view of the typewriter shown in Figure 1,

Figure 3 is a side view partly in cross section on line 33 of Figure 4,

Figure 4 is an exploded view of the present invention, partially in cross section,

Figure 5 is an isometric view of a second embodiment of the present invention showing its connection within the mechanism of a typewriter,

Figure 6 is a side view of a portion of the second embodiment of the present invention, and

Figure 7 is a side view in cross-section of a portion of the second embodiment of the present invention.

Referring in greater detail to the drawings in which like numerals indicate like parts throughout the several views, a typewriter 10 is seen inside elevation and in top plan view in Figures 1 and 2, respectively. The invention consists of a housing 11 secured to the outside surface of the typewriter 10 within which is positioned a motor 12 having a shaft 13 ending in a worm gear 14. A spur gear 15 is in mesh with the worm gear 14 and is connected to one end of a shaft 16.

A tubular housing 17 rotatable in opposite directions surrounds the shaft 16 and extends from the housing 11 inwardly to its other end where it is journaled in ied States Patent 2,791,313 Patented May 7, 1957 a bracket 18 supported on a frame piece 19 of the typewriter 10, the inner end of the shaft 16 being journaled in the housing 17 and the shaft being journaled adjacent its outer end in a bearing 9 carried by the housing 11.

An arm 20 is positioned forwardly of the platen 22 and is supported at one end for swinging movement from a position in which the other end is remote from the platen 22 to a position in which the other end is contiguous to a d spa d f o the p a e 2- sr a ly. th a 20 s connected at one end 21 to the other end of the housing 17 for movement with the latter. Rotational movement of the housing 17 in one direction :causes swinging move ment of the arm 20 from a position in which the other end 23 is remote from the platen 22 to a position in which the other end 23 is contiguous to and spaced from the platen 22 and rotational movement of the housing 17 in the opposite direction causes swinging movement of the arm 20 from the position in which the other end 23 is contiguous to and spaced from the platen 22 to the position in which the other end 23 is remote from the platen 22.

Positioned longitudinally of and within the arm 20 adjacent the other end 23 is a body 24 having a threaded opening in one side to receive the end of a cup element 25 supporting an eraser element 26, the cup element 25 being exteriorly of the arm 20 and projecti g transversely from the body 24. The arm 20 is provided adjacent the other end 23 with a longitudinally extending closed slot 23 through which the one end of the cup element 25 extends whereby the eraser 26 is connected to the arm 20 for longitudinal back and forth movement. The back and forth longitudinal movement of the eraser 26 is effected by the reciprocating movement of the actuating link 27 which is connected at one end to the body 24 and at the other end to a crank pin 28 upon the enlarged end 29 of horizontally disposed shaft 16.

In this first embodiment of the present invention, the nd o the u u housing 7 Where i P oje thin the housing 11 is formed with a cam face indicated by the reference numeral 30, which when the arm 20 is swung from its remote position to the position in which s he d 23 s co u o and pace from t e platen 22, actuates the switch elements 31 to close a circuit to energize the motor 12.

In this embodiment, the movement of the arm 20 is manual and the eraser will move back and forth across the paper held on the platen whenever the arm 20 is swung toward the platen.

Referring to Figures 5, 6 and 7, an identically formed arm 20 has its upper end 23' provided with a body 24 and the erasing element 26 supported in the cup 25'.

The one end 21 of this embodiment has a tab or ear 32 to which is p'ivotally connected one end of the actuating link 33, the other end of which is connected to a lever 34.

In this embodiment the key 35 is intended to be positioned within the frame of the typewriter with one end 36 anchored upon the same framepiece 37 which the arms supporting the keys are anchored to, two of the keys with their arms being moved and placed elsewhere within the typewriter frame. A micro switch 38 is positioned adjacent to the other end of the key 35 and is connected in circuit with the motor (not shown) within the housing 11' to drive the shaft which imparts the rectilinear motion of the erasing element of the second embodiment.

In this embodiment, the arm 20 is swung into its operating position by means of the linkage and levers of the key 35, the micro switch 38 being simultaneously closed to energize the motor which drives the eraser in the desired manner.

In each of the embodiments, it is intended that the erasbe made as an attachment for existing typewriters, while the second embodiment intends that the components of the present invention be incorporated within the structure of a typewriter.

In the first embodiment, it will be necessary to move the platen sideways to where the erasure is to be made to place it in position for erasing the misspelled or unwanted word or unwanted letter.

In the second embodiment, the platen will merely have to be backspaced a suitable number of spaces to erase whatever is to be deleted from the copy being printed. Pressure of the finger on the arm 20 or on the key 35 will control the pressure of the eraser toward the platen, so as to erase without tearing the paper on the platen.

Although an electric motor is here shown and described as driving the eraser, it is contemplated that other means may be used, such as a spring motor, to drive the eraser in its arcuate movement concentric with the platen.

While only preferred embodiments of the present invention are shown and described, other embodiments and modifications may be made and practiced within the scope of the appended claims without departing from the spirit of the invention.

What is claimed is:

1. In a typewriter having a platen, an erasing device comprising an arm positioned forwardly of the platen, said arm being supported at one end for swinging movement from a position in which the other end is remote from said platen to a position in which said other end of said arm is contiguous to and spaced from said platen, an erasing element carried by said other end of said arm and connected to said arm for longitudinal back and forth movement with respect to said other end of said arm, and means operatively connected to said erasing element for effecting the back and forth movement of the latter.

2. In a typewriter having a platen, an erasing device comprising a tubular housing rotatable in opposite directions, an arm positioned forwardly of said platen and 4 having one end connected to said housing for movement with the latter, rotational-movement of the housing in one direction causing swinging movement of the arm from a position in which the other end is remote from the platen to a position in which the other end is contiguous to and spaced from the platen and rotational movement of the housing in the opposite direction causing swinging movement of the arm from the position in which the other end is contiguous to and spaced from the platen to the position in which the other end is remote from the platen, a rotatable shaft supported in said housing, an erasing element carried by said other end of said arm and connected to said arm for longitudinal back and forth movement with respect to said other end of said arm, drive means connecting said shaft to said element, and motor means for rotatably driving said shaft.

3. In a typewriter having a platen, an erasing device comprising a tubular housing rotatable in opposite directions, an arm positioned forwardly of said platen and having one end connected to said housing for movement with the latter, rotational movement of the housing in one direction causing swinging movement of the arm from a position in which the other end is remote from the platen to a position in which the other end is contiguous to and spaced from the platen and rotational movement of the housing in the opposite direction causing swinging movement of the arm from the position in which the other end is contiguous to and spaced from the platen to the position in which the other end is remote from the platen, a rotatable shaft supported in said tubular housing, an erasing element carried by said other end of said arm and connected to said arm for longitudinal back and forth movement with respect to said other end of said arm, drive means connecting said shaft to said element, motor means for rotatably driving said shaft, and switch means connected to said arm operable to energize said motor when said arm is moved to the position in which said other end of said arm is contiguous to said platen.

References Cited in the file of this patent UNITED STATES PATENTS 1,675,570 Madigan July 3, 1928 2,246,925 Primus June 24, 1941 2,394,139 Bennett Feb. 5, 1946 

